U+2129 TURNED GREEK SMALL LETTER IOTA

U+2129 was added to Unicode in version 1.1 (1993). It belongs to the block Letterlike Symbols in the Basic Multilingual Plane.

This character is a Other Symbol and is commonly used, that is, in no specific script.

The glyph is not a composition. It has a Neutral East Asian Width. In bidirectional context it acts as Other Neutral and is not mirrored. The glyph can, under circumstances, be confused with 3 other glyphs. In text U+2129 behaves as Alphabetic regarding line breaks. It has type Other for sentence and Other for word breaks. The Grapheme Cluster Break is Any.

The Wikipedia has the following information about this codepoint:

Iota (uppercase Ι, lowercase ι; Greek: Ιώτα) is the ninth letter of the Greek alphabet. It was derived from the Phoenician letter Yodh. Letters that arose from this letter include the Roman I and J and the Cyrillic І (І, і), Yi (Ї, ї), Je (Ј, ј), and iotified letters (e.g. Yu (Ю, ю)).

In the system of Greek numerals iota has a value of 10.

Iota represents the sound [i]. In ancient Greek it occurred in both long [iː] and short [i] versions, but this distinction was lost in Koine Greek.

Iota participated as the second element in falling diphthongs, with both long and short vowels as the first element. Where the first element was long, the iota was lost in pronunciation at an early date, and was written in polytonic orthography as iota subscript, in other words as a very small ι under the main vowel, for instance ᾼ ᾳ ῌ ῃ ῼ ῳ. The former diphthongs became digraphs for simple vowels in Koine Greek.

The word is used in a common English phrase, 'not one iota', meaning 'not the slightest amount', in reference to a phrase in the New Testament: "until heaven and earth pass away, not an iota, not a dot, (King James Version: '[not] one jot or one tittle') will pass from the Law until all is accomplished." (Mt 5:18)

The word 'jot' (or iot) derives from iota.

The German, Portuguese and Spanish name for the letter J (Jot / jota) is derived from iota.